storage/v2: Add (In|Out)Degree to VertexAccessor

Reviewers: mtomic, mferencevic

Reviewed By: mferencevic

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D2309

src/storage/v2/vertex_accessor.cpp

@@ -449,4 +449,78 @@ Result<std::vector<EdgeAccessor>> VertexAccessor::OutEdges(
   return std::move(ret);
 }
 
+Result<size_t> VertexAccessor::InDegree(View view) const {
+  size_t degree = 0;
+  bool deleted = false;
+  Delta *delta = nullptr;
+  {
+    std::lock_guard<utils::SpinLock> guard(vertex_->lock);
+    deleted = vertex_->deleted;
+    degree = vertex_->in_edges.size();
+    delta = vertex_->delta;
+  }
+  ApplyDeltasForRead(transaction_, delta, view,
+                     [&deleted, &degree](const Delta &delta) {
+                       switch (delta.action) {
+                         case Delta::Action::ADD_IN_EDGE:
+                           ++degree;
+                           break;
+                         case Delta::Action::REMOVE_IN_EDGE:
+                           --degree;
+                           break;
+                         case Delta::Action::DELETE_OBJECT:
+                           LOG(FATAL) << "Invalid accessor!";
+                           break;
+                         case Delta::Action::RECREATE_OBJECT:
+                           deleted = false;
+                           break;
+                         case Delta::Action::ADD_LABEL:
+                         case Delta::Action::REMOVE_LABEL:
+                         case Delta::Action::SET_PROPERTY:
+                         case Delta::Action::ADD_OUT_EDGE:
+                         case Delta::Action::REMOVE_OUT_EDGE:
+                           break;
+                       }
+                     });
+  if (deleted) return Error::DELETED_OBJECT;
+  return degree;
+}
+
+Result<size_t> VertexAccessor::OutDegree(View view) const {
+  size_t degree = 0;
+  bool deleted = false;
+  Delta *delta = nullptr;
+  {
+    std::lock_guard<utils::SpinLock> guard(vertex_->lock);
+    deleted = vertex_->deleted;
+    degree = vertex_->out_edges.size();
+    delta = vertex_->delta;
+  }
+  ApplyDeltasForRead(transaction_, delta, view,
+                     [&deleted, &degree](const Delta &delta) {
+                       switch (delta.action) {
+                         case Delta::Action::ADD_OUT_EDGE:
+                           ++degree;
+                           break;
+                         case Delta::Action::REMOVE_OUT_EDGE:
+                           --degree;
+                           break;
+                         case Delta::Action::DELETE_OBJECT:
+                           LOG(FATAL) << "Invalid accessor!";
+                           break;
+                         case Delta::Action::RECREATE_OBJECT:
+                           deleted = false;
+                           break;
+                         case Delta::Action::ADD_LABEL:
+                         case Delta::Action::REMOVE_LABEL:
+                         case Delta::Action::SET_PROPERTY:
+                         case Delta::Action::ADD_IN_EDGE:
+                         case Delta::Action::REMOVE_IN_EDGE:
+                           break;
+                       }
+                     });
+  if (deleted) return Error::DELETED_OBJECT;
+  return degree;
+}
+
 }  // namespace storage

src/storage/v2/vertex_accessor.hpp

@@ -49,6 +49,10 @@ class VertexAccessor final {
   Result<std::vector<EdgeAccessor>> OutEdges(
       const std::vector<EdgeTypeId> &edge_types, View view) const;
 
+  Result<size_t> InDegree(View view) const;
+
+  Result<size_t> OutDegree(View view) const;
+
   Gid Gid() const { return vertex_->gid; }
 
   bool operator==(const VertexAccessor &other) const {

tests/unit/storage_v2_gc.cpp

@@ -132,6 +132,7 @@ TEST(StorageV2Gc, Sanity) {
         auto out_edges = vertex->OutEdges({}, storage::View::NEW);
         if (i % 5 != 4 && i % 3 != 2) {
           EXPECT_EQ(out_edges.GetValue().size(), 1);
+          EXPECT_EQ(*vertex->OutDegree(storage::View::NEW), 1);
           EXPECT_EQ(out_edges.GetValue().at(0).EdgeType().AsUint(), i);
         } else {
           EXPECT_TRUE(out_edges->empty());
@@ -140,6 +141,7 @@ TEST(StorageV2Gc, Sanity) {
         auto in_edges = vertex->InEdges({}, storage::View::NEW);
         if (i % 5 != 1 && i % 3 != 1) {
           EXPECT_EQ(in_edges.GetValue().size(), 1);
+          EXPECT_EQ(*vertex->InDegree(storage::View::NEW), 1);
           EXPECT_EQ(in_edges.GetValue().at(0).EdgeType().AsUint(),
                     (i + 999) % 1000);
         } else {